Pressure activated automatic source switching dispenser system

Abstract

A dispenser includes a housing that holds first and second refill units, each including a product container and a valve assembly that receives product from the product container. An actuator mechanism associates with the first refill unit and is actuated to force air into the associated valve assembly and dispense product from the valve assembly until such time as the product container associated with that valve assembly is empty. When empty, a float valve of the valve assembly prevents the actuation of the actuator mechanism and forces the actuator mechanism to associate with the second refill unit. While so associated, the first refill unit can be replaced, thus, helping to ensure that the dispenser does not run out of product.

1. A refill unit for a product dispenser comprising:
 a container holding a liquid product for dispensing; and 
 a valve assembly including:
 a valve body, 
 a holding chamber in said valve body, 
 an air inlet providing fluid communication between a source of pressurized air and said holding chamber; 
 an air inlet valve normally biased by a biasing mechanism to block said air inlet and movable against the biasing force of said biasing mechanism by pressurized air introduced through said air inlet, 
 a liquid inlet providing fluid communication between the liquid product in said container and said holding chamber, 
 a liquid inlet float valve that floats on liquid product in said holding chamber such that it blocks said liquid inlet when said holding chamber is filled with liquid product and sinks with the level of said liquid product in said holding chamber to a valve-blocking position to block movement of said air inlet valve against said biasing force of said biasing mechanism. 
 
 
     
     
       2. The refill unit as in  claim 1 , wherein the valve assembly is a foam generating valve assembly, wherein air and liquid mix to form a foam. 
     
     
       3. The refill unit as in  claim 2 , wherein said liquid product is gravity fed to said holding chamber of said foam generating valve assembly. 
     
     
       4. The refill unit as in  claim 1 , wherein pressurized air introduced at said air inlet moves said air inlet valve to unblock said air inlet and permit the entrance of air into said holding chamber, when said liquid inlet float valve floats above said valve-blocking position. 
     
     
       5. The refill unit of  claim 1 , further comprising a post mix chamber, and a holding chamber outlet valve regulating the flow of said liquid product or air or both to said post mix chamber. 
     
     
       6. The refill unit of  claim 5 , further comprising a foam media in said post mix chamber. 
     
     
       7. The refill unit of  claim 6 , wherein said foam media is selected from a mesh, as screen and a open cell foam material. 
     
     
       8. A dispenser comprising:
 a housing; 
 a first refill unit removably received in said housing and including:
 a first container holding a liquid product for dispensing, and 
 a first valve assembly including:
 a first valve body, 
 a first holding chamber in said first valve body, 
 a first air inlet; 
 a first air inlet valve normally biased by a first biasing mechanism to block said first air inlet and movable against the biasing force of said first biasing mechanism by pressurized air introduced through said first air inlet, 
 a first liquid inlet providing fluid communication between the liquid product in said first container and said first holding chamber, 
 a first liquid inlet float valve that floats on liquid product in said first holding chamber such that it blocks said first liquid inlet when said first holding chamber is filled with liquid product and sinks with the level of said liquid product in said first holding chamber to a valve-blocking position to block movement of said first air inlet valve against said biasing force of said first biasing mechanism 
 
 
 a second refill unit including:
 a second container holding a liquid product for dispensing, and 
 a second valve assembly including:
 a second valve body, 
 a second holding chamber in said second valve body, 
 a second air inlet; 
 a second air inlet valve normally biased by a second biasing mechanism to block said second air inlet and movable against the biasing force of said second biasing mechanism by pressurized air introduced through said second air inlet, 
 a second liquid inlet providing fluid communication between the liquid product in said second container and said second holding chamber, 
 a second liquid inlet float valve that floats on liquid product in said second holding chamber such that it blocks said second liquid inlet when said second holding chamber is filled with liquid product and sinks with the level of said liquid product in said second holding chamber to a valve-blocking position to block movement of said second air inlet valve against said biasing force of said second biasing mechanism; and 
 
 
 a valve assembly actuator mechanism mounted to said housing to selectively fluidly communicate with said first valve assembly and said second valve assembly, wherein, when said valve assembly actuator mechanism fluidly communicates with said first valve assembly, actuation of said valve assembly actuator mechanism causes product to be advanced through said first valve assembly, wherein said valve assembly actuator mechanism remains fluidly communicating with said first valve assembly until such time as said first container is empty of product, the emptying of said first container causing said first float valve to block the fluid communication between said valve assembly actuator mechanism and said first valve assembly, and wherein, when said first container is empty and said first float valve blocks the fluid communication between said valve assembly actuator mechanism and said first valve assembly, actuation of said valve assembly actuator mechanism causes it to move to fluidly communicate with said second valve assembly.